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<nav class="toc">
  <div class="toc-header"><strong>Contents</strong></div>
<ul>
  <li><a href="NgxQueue.html#NAME">NAME</a></li>
  <li><a href="NgxQueue.html#SYNOPSIS">SYNOPSIS</a></li>
  <li><a href="NgxQueue.html#DESCRIPTION">DESCRIPTION</a></li>
  <li><a href="NgxQueue.html#LEAK-NOTICE">LEAK NOTICE</a></li>
  <li><a href="NgxQueue.html#METHODS">METHODS</a>
    <ul>
      <li><a href="NgxQueue.html#new($data)">new($data)</a></li>
      <li><a href="NgxQueue.html#data">data</a></li>
      <li><a href="NgxQueue.html#empty">empty</a></li>
      <li><a href="NgxQueue.html#insert_head">insert_head</a></li>
      <li><a href="NgxQueue.html#insert_after">insert_after</a></li>
      <li><a href="NgxQueue.html#insert_tail">insert_tail</a></li>
      <li><a href="NgxQueue.html#head">head</a></li>
      <li><a href="NgxQueue.html#last">last</a></li>
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      <li><a href="NgxQueue.html#add">add</a></li>
      <li><a href="NgxQueue.html#foreach($block)">foreach($block)</a></li>
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      <li><a href="NgxQueue.html#NgxQueue::BACKEND()">NgxQueue::BACKEND()</a></li>
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  <li><a href="NgxQueue.html#AUTHOR">AUTHOR</a></li>
  <li><a href="NgxQueue.html#COPYRIGHT-AND-LICENSE">COPYRIGHT AND LICENSE</a></li>
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<div class="pod anchors">
<h1 id="NAME">NAME</h1>

<p>NgxQueue - Simple double linked list based nginx&#39;s ngx-queue.h</p>

<h1 id="SYNOPSIS">SYNOPSIS</h1>

<pre><code>    use NgxQueue;
    
    my $queue = NgxQueue-&gt;new;
    
    my $foo = NgxQueue-&gt;new(&#39;foo&#39;);
    my $bar = NgxQueue-&gt;new(&#39;bar&#39;);
    
    $queue-&gt;insert_tail( $foo );
    $queue-&gt;insert_tail( $bar );
    
    print $queue-&gt;head-&gt;data; # =&gt; foo
    print $queue-&gt;last-&gt;data; # =&gt; bar
    print $queue-&gt;head-&gt;next-&gt;data; # =&gt; bar
    
    $queue-&gt;foreach(sub {
        print $_-&gt;data;
    });
    # =&gt; foobar
    
    $foo-&gt;remove;
    
    $queue-&gt;foreach(sub {
        print $_-&gt;data;
    });
    # =&gt; bar</code></pre>

<h1 id="DESCRIPTION">DESCRIPTION</h1>

<p><b>This module interface is still fluid, and may change in the future.</b></p>

<p>NgxQueue provides simple double linked list. Its implementation is based <a href="http://nginx.org/">nginx</a>&#39;s ngx-queue.h</p>

<p>Using this module, you can remove a list node without list container reference. This is useful especially for some network server implementations.</p>

<p>For example,</p>

<dl>

<dt id="1.-Your-server-object-has-main-connection-queue"><a id="1"></a><a id="Your-server-object-has-main-connection-queue"></a>1. Your server object has main connection queue</dt>
<dd>

</dd>
<dt id="2.-When-new-connection-was-accepted,-server-create-a-connection-object,-and-queue-it-into-the-connection-queue."><a id="2"></a><a id="When-new-connection-was-accepted--server-create-a-connection-object--and-queue-it-into-the-connection-queue"></a>2. When new connection was accepted, server create a connection object, and queue it into the connection queue.</dt>
<dd>

</dd>
<dt id="3.-When-some-error-occurred,-connection-object-can-remove-itself-from-server&#39;s-connection-queue-without-server-object-reference."><a id="3"></a><a id="When-some-error-occurred--connection-object-can-remove-itself-from-server-s-connection-queue-without-server-object-reference"></a>3. When some error occurred, connection object can remove itself from server&#39;s connection queue without server object reference.</dt>
<dd>

</dd>
</dl>

<p>This make your code more clean and simple.</p>

<h1 id="LEAK-NOTICE"><a id="LEAK"></a>LEAK NOTICE</h1>

<p>Once NgxQueue object is added to other queue by <code>insert_tail</code>, <code>insert_head</code>, or <code>insert_after</code>, its object refcount will be retained until removed.</p>

<p>So you should call <code>remove</code> when destroying your container, otherwise it causes memory leak.</p>

<p>If you want to use single queue container, following container class will help:</p>

<pre><code>    package MyQueueContainer;
    use strict;
    use warning;
    use parent &#39;NgxQueue&#39;;
    
    sub DESTROY {
        $_[0]-&gt;foreach(sub { $_-&gt;remove });
    }
    
    1;</code></pre>

<h1 id="METHODS">METHODS</h1>

<h2 id="new($data)"><a id="new"></a><a id="new-data"></a>new($data)</h2>

<pre><code>    my $q = NgxQueue-&gt;new(&#39;some data&#39;);</code></pre>

<p>Create new NgxQueue object. <code>$data</code> is optional.</p>

<p>If you pass some <code>$data</code>, the data is available by calling <code>$obj-&gt;data</code>.</p>

<h2 id="data">data</h2>

<p>Get some data associated the object.</p>

<pre><code>    my $data = $q-&gt;data;</code></pre>

<h2 id="empty">empty</h2>

<p>Check queue is empty.</p>

<pre><code>    my $q = NgxQueue-&gt;new;
    $q-&gt;empty; # =&gt; true
    
    $q-&gt;insert_tail( NgxQueue-&gt;new(&#39;foo&#39;) );
    $q-&gt;empty; # =&gt; false</code></pre>

<h2 id="insert_head">insert_head</h2>

<p>Insert a queue where head of container</p>

<pre><code>    my $q = NgxQueue-&gt;new;
    $q-&gt;insert_head( NgxQueue-&gt;new(&#39;foo&#39;));
    $q-&gt;insert_head( NgxQueue-&gt;new(&#39;bar&#39;));
    
    $q-&gt;foreach(sub { print $_-&gt;data }); # =&gt; barfoo</code></pre>

<h2 id="insert_after">insert_after</h2>

<p>Insert a queue_a where after the queue_b</p>

<pre><code>    my $q = NgxQueue-&gt;new;
    my $queue_a = NgxQueue-&gt;new(&#39;a&#39;);
    $q-&gt;insert_head($queue_a);
    
    $queue_a-&gt;insert_after( NgxQueue-&gt;new(&#39;b&#39;) );
    
    $q-&gt;foreach(sub { print $_-&gt;data }); # =&gt; ab</code></pre>

<h2 id="insert_tail">insert_tail</h2>

<p>Insert a queue where last of the container</p>

<pre><code>    my $q = NgxQueue-&gt;new;
    $q-&gt;insert_tail( NgxQueue-&gt;new(&#39;foo&#39;) );
    $q-&gt;insert_tail( NgxQueue-&gt;new(&#39;bar&#39;) );
    
    $q-&gt;foreach(sub { print $_-&gt;data }); # =&gt; foobar</code></pre>

<h2 id="head">head</h2>

<p>Get head of queue object from container.</p>

<pre><code>    my $q = NgxQueue-&gt;new;
    $q-&gt;insert_head( NgxQueue-&gt;new(&#39;foo&#39;) );
    
    print $q-&gt;head-&gt;data; # =&gt; foo</code></pre>

<h2 id="last">last</h2>

<p>Get last of queue object from container.</p>

<pre><code>    my $q = NgxQueue-&gt;new;
    $q-&gt;insert_tail( NgxQueue-&gt;new(&#39;foo&#39;) );
    
    print $q-&gt;last-&gt;data; # =&gt; foo</code></pre>

<h2 id="next">next</h2>

<p>Get next queue object from queue object.</p>

<pre><code>    my $q = NgxQueue-&gt;new;
    
    my $foo = NgxQueue-&gt;new(&#39;foo&#39;);
    my $bar = NgxQueue-&gt;new(&#39;bar&#39;);
    
    $q-&gt;insert_tail( $foo );
    $q-&gt;insert_tail( $bar );
    
    print $foo-&gt;next-&gt;data; # =&gt; bar</code></pre>

<h2 id="prev">prev</h2>

<p>Get prev queue object from queue object.</p>

<pre><code>    my $q = NgxQueue-&gt;new;
    
    my $foo = NgxQueue-&gt;new(&#39;foo&#39;);
    my $bar = NgxQueue-&gt;new(&#39;bar&#39;);
    
    $q-&gt;insert_tail( $foo );
    $q-&gt;insert_tail( $bar );
    
    print $bar-&gt;prev-&gt;data; # =&gt; foo</code></pre>

<h2 id="remove">remove</h2>

<p>Remove queue object from container.</p>

<pre><code>    my $q = NgxQueue-&gt;new;
    my $foo = NgxQueue-&gt;new(&#39;foo&#39;);
    my $bar = NgxQueue-&gt;new(&#39;bar&#39;);
    my $buz = NgxQueue-&gt;new(&#39;buz&#39;);
    
    $q-&gt;insert_tail( $foo );
    $q-&gt;insert_tail( $bar );
    $q-&gt;insert_tail( $buz );
    
    $bar-&gt;remove;
    
    $q-&gt;foreach(sub { print $_-&gt;data }); # =&gt; foobuz</code></pre>

<h2 id="split">split</h2>

<p>Split single container to double containers.</p>

<pre><code>    my $q = NgxQueue-&gt;new;
    my $foo = NgxQueue-&gt;new(&#39;foo&#39;);
    my $bar = NgxQueue-&gt;new(&#39;bar&#39;);
    my $buz = NgxQueue-&gt;new(&#39;buz&#39;);
    my $bla = NgxQueue-&gt;new(&#39;bla&#39;);
    
    my $q2 = NgxQueue-&gt;new;
    $q-&gt;split($buz, $q2);
    
    $q-&gt;foreach(sub { print $_-&gt;data }); # =&gt; foobar
    $q2-&gt;foreach(sub { print $_-&gt;data }); # =&gt; buzbla</code></pre>

<h2 id="add">add</h2>

<p>Combine two containers into one.</p>

<pre><code>    my $q1 = NgxQueue-&gt;new;
    my $q2 = NgxQueue-&gt;new;
    
    $q1-&gt;insert_tail( NgxQueue-&gt;new(&#39;foo&#39;);
    $q1-&gt;insert_tail( NgxQueue-&gt;new(&#39;bar&#39;);
    
    $q2-&gt;insert_tail( NgxQueue-&gt;new(&#39;hoge&#39;) );
    $q2-&gt;insert_tail( NgxQueue-&gt;new(&#39;fuga&#39;) );
    
    $q1-&gt;add($q2);
    
    $q1-&gt;foreach(sub { print $_-&gt;data }); # =&gt; foobarhogefuga</code></pre>

<h2 id="foreach($block)"><a id="foreach"></a><a id="foreach-block"></a>foreach($block)</h2>

<p>foreach loop for the container. Each object represented as <code>$_</code> in the loop block.</p>

<h1 id="FUNCTIONS">FUNCTIONS</h1>

<h2 id="NgxQueue::BACKEND()"><a id="NgxQueue"></a><a id="NgxQueue::BACKEND"></a>NgxQueue::BACKEND()</h2>

<p>Return backend implementation: &#39;XS&#39; or &#39;PP&#39;</p>

<h1 id="AUTHOR">AUTHOR</h1>

<p>Daisuke Murase &lt;typester@cpan.org&gt;</p>

<p>Masayuki Matsuki &lt;songmu@cpan.org&gt;</p>

<h1 id="COPYRIGHT-AND-LICENSE"><a id="COPYRIGHT"></a>COPYRIGHT AND LICENSE</h1>

<p>ngx-queue.h:</p>

<pre><code>    /* 
     * Copyright (C) 2002-2013 Igor Sysoev
     * Copyright (C) 2011-2013 Nginx, Inc.
     * All rights reserved.
     *
     * Redistribution and use in source and binary forms, with or without
     * modification, are permitted provided that the following conditions
     * are met:
     * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS&#39;&#39; AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     */</code></pre>

<p>Other part:</p>

<pre><code>    Copyright (c) 2013 Daisuke Murase All rights reserved.
    
    This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.</code></pre></div>

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